POCUS

Question 1

Ultrasound is defined as sound with a frequency greater than ___________ hz (the human hearing limit).

Answer 1

20,000 hz

Question 2

What range do ultrasound devices operate at?

Answer 2

2 - 18 megahertz

Question 3

What type of ultrasound probe provides the best resolution in exchange for poor penetration?

Answer 3

Linear
High frequency

Question 4

What type of ultrasound probe provides decent resolution and decent penetration?

Answer 4

Curvilinear

Question 5

What type of ultrasound probe provides the best penetration in exchange for poor resolution?

Answer 5

Phased
Low frequency

Question 6

What aspect of the ultrasound probe converts electricity into sound?

Answer 6

Piezoelectric elements

Question 7

Is the output from the ultrasound probe constant? Why or why not?

Answer 7

No because a “listening” period is needed for returning signals.

Question 8

What tissue allows for the quickest sound conduction?

Answer 8

Bone

Question 9

What then would have the slowest conduction speed?

Answer 9

Air

Question 10

What zone is indicated by 1 in the figure below?

Answer 10

Fresnel Zone (near field)
Decent lateral resolution in this region

Question 11

What zone is indicated by 2 in the figure below?

Answer 11

Fraunhofer Zone (far field)
Poor lateral resolution in this region

Question 12

What zone is indicated by 3 in the figure below?

Answer 12

Focal Zone (ultrasound is narrowest and beam intensity is greatest here.)
Best lateral resolution in this region

Question 13

What is impedance?

Answer 13

The resistance to ultrasound propagation as it moves through a medium.

Question 14

What has the greatest impedance?

Answer 14

Greatest impedance = bone

Question 15

What has the least impedance?

Answer 15

Least impedance = air

Question 16

What is ultrasound reflection?

Answer 16

Reflection of ultrasound waves back to the probe

Question 17

What has the highest reflection property?

Answer 17

Air

Question 18

What tissue is highest in reflection?

Answer 18

Bone has highest reflection

Question 19

What is mirror artifact?

Answer 19

Artifact where tissue is mirrored on the other side of a structure (diaphragm/liver example)

Question 20

What is refraction?

Answer 20

Occurs when ultrasound strikes two tissues with different impedance values.

Question 21

What is edge artifact?

Answer 21

Artifact occurring at the edges of smooth or rounded structures creating a shadow at structures edge.

Question 22

What is ultrasound attenuation?

Answer 22

Loss of amplitude & intensity the deeper ultrasound waves penetrate. (due to absorption, refraction, & reflection)
Linear probe (due to higher frequency)

Question 23

What is ultrasound absorption?

Answer 23

Occurs as ultrasound wave travels through a medium losing energy.

Question 24

What is Anechoic? What is an example?

Answer 24

Structures that appear black due to having no internal echoes.
Ex. Blood vessels, bladder, cysts, etc.

Question 25

What is hypoechoic? What are tissue examples?

Answer 25

Structures that appear darker than surrounding tissue. Ex. kidney compared to spleen.

Question 26

What is hyperechoic? What are tissue examples?

Answer 26

Structures that are brighter than the surrounding tissue. Ex. Fatty tumors & bone

Question 27

What type of artifact is noted in the picture below?

Answer 27

Shadowing (occurs from bone reflecting back most ultrasound waves, and the rest attenuating quickly).

Question 28

What type of artifact is noted in the picture below?

Answer 28

Posterior Acoustic Enhancement (occurs from passing through low impedance tissue).

Question 29

What does M-mode do in the ultrasound machine?

Answer 29

Gives a motion over time display. Lung sliding, fetal heart rate, etc.

Question 30

What color would the doppler appear based on the picture evaluating the radial artery below?

Answer 30

Red (blood moving towards doppler)

Question 31

What color would the doppler appear based on the picture evaluating the radial artery below?

Answer 31

Blue (blood moving away from doppler)

Question 32

When getting a pulse-wave doppler (PWD) how should the probe be positioned?

Answer 32

Parallel with the direction of flow. (perpendicular will cause flattening of the waveform)

Question 33

What doppler technique is depicted below?

Answer 33

Sliding (movement along long axis)

Question 34

What doppler technique is depicted below?

Answer 34

Sweeping (movement along short axis)

Question 35

What doppler technique is depicted below?

Answer 35

Tilting/Fanning (tilting along short axis)

Question 36

What doppler technique is depicted below?

Answer 36

Rocking/Heeling (tilting along long axis)

Question 37

What doppler technique is utilized to change between a short and long axis view?

Answer 37

Rotating

Question 38

Is an out-of-plane or in-plane view depicted below?

Answer 38

Out-of-plane

Question 39

Is an out-of-plane or in-plane view depicted below?

Answer 39

In-plane